While Novak Djokovic, Andy Murray, Roger Federer and Rafael Nadal are the undisputed top four in world tennis, not far behind them stands a 24-year-old Argentinian by the name of Juan Martin del Potro, who has both the game and the stature to look the leading quartet in the eye.

Seventh in the current ATP Rankings, a bronze medallist at last year’s London Olympics and a US Open champion at the age of only 19, the 6’4-tall Del Potro spoke to FIFA.com at his training base in Buenos Aires, where he is recovering from a virus that has forced him to skip the French Open, the second of this year’s Grand Slam events. The topic of discussion in the first instalment of this two-part interview was not tennis, however, but football, the Argentinian’s other major sporting passion.

FIFA.com: Is there a place for football in your hectic playing schedule?
Juan Martin del Potro: Absolutely. It’s the number-one for me. I really love it. I watch football in my spare time and I play it with my friends too. I don’t get a lot of free time in Buenos Aires, but we’ve got some teams set up over in Tandil and every time I go there for a few days we have a few games before the sun goes down or before a barbecue. I follow Boca Juniors closely but I like all types of football to be honest, and when I’m in Argentina I can see a bit more of the team I support.

Football and a barbecue: is that a typical day with your friends?
We have a game at about six or seven in the evening and we play for an hour on a seven- or nine-a-side pitch. We don’t play on a full-size pitch because you have to run around lot and I already do plenty of that when I play tennis (laughs). The winners don’t have to do anything later. The losing team has to set the table, do the shopping and the barbecue and tidy everything up afterwards. In Tandil we’ve got really good salamis and cheeses and the losing team always has to do the snacks as well. We stay up late and have a really good time.

Which position do you play in? With your height you must be a centre-half or centre-forward.
Centre-forward. I’ve enjoyed playing there since I was a kid. I used to play a lot in the centre of defence too. I liked the position with all the passing and running. I ended up playing up front though and the fact is I love the game. Actually I like it even more than tennis, which is like a job to me now. I still have this desire deep down to play a competitive match for any club that will have me when I finish my tennis career. I want to experience that intensity and play for points, which is what I did when I was young.

Which club did you play for?
I played for Independiente de Tandil and we were always fighting for the title. We played in a lot of regional and national competitions, where we came up against the likes of Boca, Newell’s, Colon, Racing Club and Independiente. You can imagine how big the gap was between us and big teams like them but I just thought it was fantastic. You’d play Boca and they were all there in their matching kit and boots and with the same balls, and there we were with the little bit of kit we had. We were kids living a dream, though. When I was about 12 or 13 I had to choose between tennis and football and I went for tennis.

I like it even more than tennis, which is like a job to me now. I still have this desire deep down to play a competitive match for any club that will have me when I finish my tennis career.

Juan Martin del Potro

How difficult was it for you to make that choice?
Really, really hard. My football coach spoke a lot with my tennis coach. Neither of them wanted to let me go, and the fact is I always liked football more. The decision came about, though, because there was a very important football tournament at the same time as a South American championship for 12-year-olds in Brazil. As I’d never been out of the country, I said: 'I’m going to Brazil to play tennis.' It was the first time I’d been on a plane and my first tennis tournament and I ended up being the best player. That came as a complete surprise for everyone, for my family and my coach. When I got back they said I had a chance of making it and that it would be difficult for me to carry on playing both sports, which meant I had a decision to make. I said tennis, and I spent three of four months just playing that. Then I said to myself: ‘No, it’s football for me.’ So I put the racket away, carried on with my studies at school and played nothing else but football. That’s the way things were till I was nearly 14, which is when I lost enthusiasm for it and felt something for tennis instead. So I got my head down and devoted myself to tennis.

Do you think you would have had a good career if you’d stuck with football?
From what they said when I was a boy, yes. They said I was like Marangoni (Claudio, who played for Independiente and Boca in the 1980s) because of my physique and the way I played. But then I started growing and I wasn’t as nimble on my feet. That’s why they put me up front. I loved playing football. I’d kick a ball against a wall for an hour before tennis training and afterwards I’d spend another hour playing football. Some of my team-mates from back then play in the Argentino A (the national third tier) for Independiente. I don’t know if I’d have made it with Boca or another big team but I definitely would have made it with them.

What’s your first football memory?
Kid’s tournaments that we’d play on five-a-side pitches, when I was about 8 or 9 and already playing against kids who were a couple of years older. I’d be wearing football kit every weekend from eight in the morning through to nine at night, playing match after match after match.

Did you go to sleep wearing your Boca jersey?
Yes, yes. I was all ready the day before. I had my boots at the ready and my grandfather would get me a ball. I had the lot. I remember a funny incident when I was about 11 or 12, playing in a tournament in Tandil. The parents of the opposing players were saying: ‘That kid’s really big. We should check his papers’. They’d hit all these crosses and I’d head or kick the ball away further than anyone, and really hard too. People would always talk about whether I was older than I said I was.

Why Boca?
Because of my grandfather. There are a lot of Boca fans in my family, my dad included. When you’re young you start supporting a club even though you don’t understand that much, and then you start to watch more and more games. I caught Boca’s most successful era and that’s when I became a real fan. I was lucky enough to meet a lot of the players and to become friends with some of the club’s legends. For me as a fan and a person it doesn’t get any better than that.

Log on to FIFA.com this Tuesday for part two of this interview.